Domain Extension Overview (TLDs)

Generic Top-Level Extensions (gTLD)

A generic top-level domain (gTLD) is a top-level domain used (at least in theory) by a particular class of organization. These are three or more letters long, and are named for the type of organization that they represent (for example, .com for commercial organizations).

Country Code Top-Level Extensions (ccTLD)

A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country or a dependent territory. ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. Creation and delegation of ccTLDs is performed by the Internet Assigned Numbers Authority (IANA), and with certain exceptions noted below corresponds to the ISO 3166-1 alpha-2 country codes maintained by the ISO 3166 Maintenance Agency.

Country Code Second-Level Extensions (ccSLD)

A country code second-level domain (ccSLD) is a second-level domain to a country code top-level domain. It may be set apart by the domain name registry for the registration of third-level domains or registered to a third party as a subdomain. Many registries reuse common top-level domain names at the second-level such as "com", "net" and "org", e.g. .com.sg.